Electromagnet.



No. 824,046. PATENTED JUNE 19, 1906.

I O. F. A. STURTS.

BLEGTROMA'GNET.

APPLICATION HLBD APR.28,1905.

FIG

15 W/ 7/1 55555 //v MFA 70R" CHARLES F. A. STURTS, OF SAN FRANCISCO,CALIFORNIA.

ELECTROMAGNET.

Specification of Letters Patent.

Patented June 19, 1906.

Application filed April 28,1905. Serial No. 257,878.

To all whom, it may concern:

Be it known that I, CHARLEs F. A. STURTs, a citizen of the UnitedStates, residing at San Francisco, in the county of San Francisco andState of California, have invented certain new and useful Improvementsin Electromagnets, of which the following is a specification.

My invention relates to electromagnets capable of being used for all thepurposes in general for which such magnets are adapted, but havingespecial reference to employment in situations where it is desirablethat their operation shall be noiseless.

In constructing electrical winding apparatus for timepieces, such asthat shown in my application for patent, Serial No. 21 1,056, filed June3, 1904, I have found that in using ordinary magnets for operating thewinding mechanism the direct pull of the armature into contact with thepoles causes a sharp click, and as this noise is repeated many times inthe course of a day it is to some eX- tent objectionable. The magnetwhich is the subject of the present application obviates this objection,its operation being noiseless, and this advantage is obtained without inany way affecting or detracting from its efiiciency.

I have shown my improved magnet in the accompanying drawings inconnection with an arbor and ratchet-wheel as illustrative of one of itspractical uses.

Figure 1 is a plan view of the magnet and armature in connection with aratchet-wheel and arbor. Fig. 2 is a sectional elevation of the magnetand armature. Fig. 3 is a sectional elevation of the same at rightangles, one spool having been removed.

The operative parts of the invention are shown as mounted upon a plate1, which may be a support for a clock-movement or any other support. Ashaft or arbor 2, journaled in the bridge 3, attached to the plate 1,carries a ratchet 4. For these devices any others can be substituted, asthey are shown here only to illustrate one derivation of motion from thearmature of the magnet. The ratchet-wheel and arbor may be supposed toform part of an electrical winding system for timepieces, the ratchetbeing moved intermittently, and so operating the arbor and any partsconnected to it.

The electromagnet is composed, as usual, of two spools 5 6, havingproper windings and provided with interior cores 7 8 the ends of whichare preferably substantially even with the ends of the spools and formthe poles. The cores are secured by countersunk screws 9 11 to the base12, so that the cores are in magnetic connection. The basepiece 12 has ahole between the spools, in which is set the hollow standard or bearing13, the end of which is reduced to fit said hole. The shoulder thusformed rests upon the base-piece.

Mounted loosely in the bearing 13 is a rod 14, one end of which projectsbeyond such bearing. The bore of the bearing is slightly reduced nearits end adjacent to the basepiece, so as to form a stop for the rod 14,and the reduced part is threaded. A hole 15 in the plate 1 admits ascrew 16, which enters and engages with the threaded part and can becaused to bear upon the end of rod 14, so that the osition of such rod14 can be accurately a justed.

The projecting end of rod 14 carries the armature 17, which is a bar ofsoft iron of such length as to extend in both directions to and acrossthe magnet-poles; but the adjustment is such that the armature is neverin contact with the oles. The magnet is thus adapted to swing from theposition shown by'full lines in Fig. 1 to the position shown by dottedlines in the same figure. The normal position when no current is in thecoils is inclined to a line drawn between the centers of the two poles,as shown. When the magnet is energized, the armature swings by magneticattraction to a position in which it is directly opposite and adjacentto said poles, but not in contact with either of them.

A coil-spring 18 is connected to the armature-rod 14 and to the standard13, the tension of which is suflicient to hold the armature in itsnormal position and to return it to that position when the circuit isopen. The spring is located between the armature and the coils, so as tobe protected and out of the way, and the magnetic attraction issufficient to overcome the spring when the circuit is closed.

As illustrating the transmission of mechanical energy by the armature Ihave shown an arm 19, secured to the rod 14 and projecting outwardly.This arm has a stud 21, which operates the ratchet one tooth wheneverthe armature is attracted. This arm is preferably made of thin elasticmetal, so that it can be moved sidewise by the ratchet and will thenspring in back of the next tooth, and

and holds such rod in place.

The operation of the device will be readily understood. hen themagnet-coils are energized, the attraction of the poles draws the endsof the armature in opposite directions to the position opposite andadjacent to them. As the armature is never in contact with either pole,its operation is noiseless, and the click caused by sudden sharp contactwith the metal poles is done away with. At the same time it is perfectlyeffective as a means for transmitting mechanical energy.

In order to prevent the possibility of any noise caused by the armaturestriking its stops, I prefer to provide such stops with surfaces orcushions of leather or other suitable material, as shown at 25.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. In an electromagnet, the combination withthe spools and the polepiece or base upon which they are mounted, of a hollow standard on saidbase, an adjustable rod j ournaled in said standard and an armaturecarried by said rod.

2. In an electromagnet, the combination with the spools and the polepiece or base upon which they are mounted, of a hollow standard on saidbase, an adjustable rod journaled in said standard and an armaturecarried by said rod, and means for adjusting said rod in said standard.

3. In an electromagnet the combination with the spools and the polepiece or base upon which they are mounted, of a hollow standard on saidbase, an adjustable rod journaled in said standard and an armaturecarried by said rod, and a screw entering said standard and adapted tobear upon said rod.

4. In an electromagnet, the combination with the spools and the polepiece or base upon which they are mounted, of a hollow standard on saidbase, a rod journaled, in said standard, an armature carried by saidrod, and a coiled spring connecting said standard and said rod.

5. In an electromagnet, the combination with the spools and the polepiece or base upon which they are mounted, of a hollow standard on saidbase, an adjustable rod journaled in said base, a coiled springconnecting the rod to the base, and an armature carried by said rod,substantially as described.

6. In an electromagnet, the combination with the magnetspools of anintermediate hollow standard or bearing, a rod j ournaled therein andprojecting beyond it, an arma ture carried by said rod, and athree-branched bracket having one branch secured to said standard, theother branches of which are respectively stops for the opposite ends ofthe armature.

7. In an electromagnet, the combination with the spools and the polepiece or base upon which they are mounted, of a hollow standard on saidbase, an adjustable rod journaled in said standard, an armature carriedby said rod, and an arm of thin elastic material having one endconnected to said adjustable rod for transmitting power derived from themovement of the armature.

In testimony whereof I have affixed my signature, in presence of twowitnesses, this 10th day of April, 1905.

CHARLES F. A. STURTS.

Witnesses:

CELESTE ANsELL, HENRIETTE BURT.

